Research On Current-carrying Friction Characteristics And Friction Modeling Of Pantograph-catenary Under Fluctuating Contact Force

In electrified railway,a pair of current-carrying friction pairs are composed of pantograph slide plate and catenary wire.This pair of friction and wear characteristics seriously affect the life of pantograph slide plate and catenary wire and the current-collecting quality of locomotive.Friction is an important factor causing friction and wear of pantograph slide plate.At the same time,the actual contact force between pantograph and catenary fluctuates periodically.This fluctuating contact force affects the change of friction force at all times,and this effect becomes more and more significant with the increase of locomotive speed.Therefore,the research on current-carrying friction of pantograph and catenary under fluctuating contact force has practical significance,which can ensure the stable and safe operation of high-speed train,reduce material wear and save cost.In this thesis,a sliding electric contact test machine developed by ourselves is used to simulate the contact condition of pantograph and catenary of high-speed railway by metal impregnated carbon slide and pure copper contact wire.The characteristic curves of friction coefficient varying with contact force fluctuating frequency,fluctuating amplitude,current and sliding speeds are obtained and analyzed theoretically.The results show that when the fluctuating contact force and current are constant,the friction coefficient changes slightly with the increase of the fluctuating frequency of the contact force,but shows a slight upward trend.;When the fluctuating frequency of contact force and current are constant,the friction coefficient increases with the increase of the fluctuating amplitude of contact force;When the fluctuating frequency and fluctuating amplitude of contact force are constant,the friction coefficient decreases with the increase of current;When the fluctuating frequency of contact force and current are constant,the friction coefficient increases with the increase of sliding speed.Based on the experimental data,a friction coefficient model related to fluctuating contact force and current is established,and the Stribeck friction model related to velocity is combined to correct the friction coefficient in the friction model.Finally,a pantograph-catenary current-carrying friction model related to velocity,fluctuating contact force and current is established.The unknown parameters of the model was identified by the Levenberg-Marquardt and Universal Global Optimization,The validity of the model is verified by comparing the unused friction data with the predicted value of the model.Which provides a reference for the prediction of the friction of pantograph-catenary system and research on friction and wear properties.